1. Press the Volume keys to adjust the volume.
   
2. Press the Volume Down key until the Silent icon is displayed to enable silent mode.
   
3. Press the Volume Down key again until the Vibrate icon is displayed to enable vibrate.
   
4. Tap the Settings icon to access additional volume settings.
   
5. To change the ringtone or adjust notification alerts, swipe down from the top of the screen with two fingers. Tap SETTINGS. Scroll to “PHONE”.
   
6. Tap Sound & notification.
   
7. To change the default ringtone, scroll to “INCOMING CALLS,” then tap Ringtone.
   
8. Tap the Desired option. Then tap APPLY.
   Note: For steps to assign a ringtone to a contact, please see the 'Contacts' tutorial.
   
9. To change notification alerts sound, tap Notification sound, then tap the desired option.
   
10. To block or unblock notifications from appearing when the device is locked, tap When device is locked. Then tap the Desired option.